Use of isatin derivatives as ion channel activating agents

ABSTRACT

The present invention relates to ion channel activating agents. More particularly, the present invention relates to a particular class of chemical compounds that has proven useful as openers of SK Ca  and IK Ca  channels. In further aspects, the present invention relates to the use of these SK/IK channel activating agents for the manufacture of medicaments and pharmaceutical compositions comprising the SK/IK channel activating agents. The SK/IK channel activating agents of the invention are useful for the treatment or alleviation of diseases and conditions associated with the SK/IK channels, in particular respiratory diseases such as asthma, cystic fibrosis, chronic obstructive pulmonary disease and rhinorrhea, convulsions, vascular spasms, coronary artery spasms, renal disorders, polycystic kidney disease, bladder spasms, urinary incontinence, bladder outflow obstruction, irritable bowel syndrome, gastrointestinal dysfunction, secretory diarrhea, ischaemia, cerebral ischaemia, ischaemic heart disease, angina pectoris, coronary heart disease, traumatic brain injury, psychosis, anxiety, depression, dementia, memory and attention deficits, Alzheimer&#39;s disease, dysmenorrhea, narcolepsy, Reynaud&#39;s disease, intermittent claudication, Sjorgren&#39;s syndrome, migraine, arrhythmia, hypertension, absence seizures, myotonic muscle dystrophia, xerostomi, diabetes type II, hyperinsulinemia, premature labor, baldness, cancer, and immune suppression.

TECHNICAL FIELD

[0001] The present invention relates to ion channel activating agents.More particularly, the present invention relates to a particular classof chemical compounds that has proven useful as openers of SK_(Ca) andIK_(Ca) channels. In further aspects, the present invention relates tothe use of these SK/IK channel activating agents for the manufacture ofmedicaments, and pharmaceutical compositions comprising the SK/IKchannel activating agents.

[0002] The SK/IK channel activating agents of the invention are usefulfor the treatment or alleviation of diseases and conditions associatedwith the SK/IK channels, in particular respiratory diseases such asasthma, cystic fibrosis, chronic obstructive pulmonary disease andrhinorrhea, convulsions, vascular spasms, coronary artery spasms, renaldisorders, polycystic kidney disease, bladder spasms, urinaryincontinence, bladder outflow obstruction, irritable bowel syndrome,gastrointestinal dysfunction, secretory diarrhoea, ischaemia, cerebralischaemia, ischaemic hearth disease, angina pectoris, coronary hearthdisease, traumatic brain injury, psychosis, anxiety, depression,dementia, memory and attention deficits, Alzheimer's disease,dysmenorrhea, narcolepsy, Reynaud's disease, intermittent claudication,Sjorgren's syndrome, migraine, arrhythmia, hypertension, absenceseizures, myotonic muscle dystrophia, xerostomi, diabetes type II,hyperinsulinemia, premature labour, baldness, cancer, and immunesuppression.

BACKGROUND ART

[0003] Ion channels are transmembrane proteins, which catalyse thetransport of inorganic ions across cell membranes. The ion channelsparticipate in processes as diverse as the generation and timing ofaction potentials, synaptic transmissions, secretion of hormones,contraction of muscles, etc.

[0004] Many drugs exert their effects via modulation of ion channels.Examples are anti-epileptic compounds like Phenytoin and Lamotrigine,which block voltage dependent Na⁺-channels in the brain,anti-hypertensive drugs like Nifedipine and Diltiazem, which blockvoltage dependent Ca²⁺-channels in smooth muscle cells, and stimulatorsof insulin release like Glibenclamide and Tolbutamide, which block anATP-regulated K⁺-channel in the pancreas.

[0005] All mammalian cells express potassium (K⁺) channels in their cellmembranes, and the channels play a dominant role in the regulation ofthe membrane potential. In nerve and muscle cells they regulate thefrequency and form of the action potential, the release ofneurotransmitters, and the degree of broncho- and vasodilation.

[0006] From a molecular point of view, the K⁺ channels represent thelargest and most diverse group of ion channels. For an overview they canbe divided into five large subfamilies: Voltage-activated K⁺ channels(K_(V)), long QT related K⁺ channels (KvLQT), inward rectifiers(K_(IR)), two-pore K⁺ channels (K_(TP)), and calcium-activated K⁺channels (K_(ca)).

[0007] The latter group, the Ca²⁺-activated K⁺ channels, consists ofthree well-defined subtypes: SK channels, IK channels and BK channels.SK, IK and BK refer to the single-channel conductance (Small,Intermediate and Big conductance K channel). The SK, IK, and BK channelsexhibit differences in e.g. voltage- and calcium-sensitivity,pharmacology, distribution and function.

[0008] Ca²⁺-activated SK channels are present in many central neuronsand ganglia, where their primary function is to hyperpolarize nervecells following one or several action potentials to prevent long trainsof epileptogenic activity to occur. The SK channels are also present inseveral peripheral cells including skeletal muscle, gland cells, livercells, and T-lymphocytes.

[0009] The significance of SK channels in normal skeletal muscle is notclear, but their number is significantly increased in denervated muscle,and the large number of SK channels in the muscle of patients withmyotonic muscle dystrophia suggest a role in the pathogenesis of thedisease.

[0010] A number of blockers of SK channels exist, e.g. apamin,atracurium, pancuronium, and tubocurarine, and they are all positivelycharged molecules which act as pore blockers.

[0011] The Ca²⁺-activated IK channel shares a number of characteristicswith the Ca²⁺-activated SK channel, since it is highly K-selective, isactivated by sub-micromolar concentrations of Ca²⁺, and has an inwardlyrectifying conductance. However, there are also striking differences.The unit conductance of the IK channel is 4-5 fold higher than that ofthe SK channel, and the distribution of the IK channel is restricted tothe blood and vasculature. Thus, the IK channel is not expressed in thenervous system and in muscle, but in endothelial cells, cells ofepithelial origin and in red blood cells.

[0012] In the red blood cells, where the IK channel has been denominatedthe Gardos channel, a rise in the concentration of intracellular Ca²⁺opens the channel and causes potassium loss and cell dehydration, acondition which is exacerbated in sickle cell anemia. Promisingtherapeutic approaches for sickle cell anemia involve specific block ofthe IK channel.

[0013] IK channels have also been implicated in the microvasculature ofthe kidney, where they may be responsible for the vasodilatory effectsof bradykinin. The decrease in blood pressure during septic shock iscaused by an increased NO production by the endothelial cells, and theIK channels in these cells are responsible for maintaining the Ca²⁺influx activating the Ca²⁺-sensitive NO-synthase.

[0014] In brain capillary endothelial cells, IK channels, activated byendothelin that is produced by neurons and glia, shunt excess K⁺ intothe blood. Neurotrophilic granulocytes, i.e. mobile phagocytic cellsthat defend the body against microbial invaders, undergo largedepolarisation subsequent to agonistic stimulation, and IK channels havebeen implicated in depolarising the stimulated granulocyte.

[0015] EP 432,648 describes isatin derivatives having excitatory aminoacid antagonising activity. However, EP 432,648 does not teach orsuggest any SK or IK channel activity associated with these isatincompounds.

SUMMARY OF THE INVENTION

[0016] According to the present invention it has now been found that aparticular group of isatin derivatives possess valuable activity asopeners of SK_(Ca) and/or IK_(Ca) channels, and the invention isdirected to isatin derivatives for use as SK/IK channel activatingagents.

[0017] In its first aspect the invention relates to the use of a isatinderivative represented by the general formula

[0018] or a pharmaceutically acceptable salt or an oxide or a hydratethereof, wherein,

[0019] R¹ represents hydrogen; an alkyl group; a cycloalkyl group; anacyl group; a phenyl or a benzyl group, which phenyl and benzyl groupsmay be substituted one or more times with substituents selected fromhalogen, —NO₂, —CN, —CF₃, alkyl, cycloalkyl, hydroxy, and alkoxy; agroup of the formula —CH₂CN; a group of the formula —CH₂CO₂R′, whereinR′ represents hydrogen or alkyl; a group of the formula—CH₂CONR^(IV)R^(V), wherein R^(IV) and R^(V) independently representshydrogen, alkyl, phenyl or benzyl, which phenyl and benzyl groups mayoptionally be substituted one or more times with halogen and/or alkyl,or R^(IV) and R^(V) together with the N-atom to which they are attachedform a heterocyclic 4 to 7 membered monocyclic group, which heterocyclicgroup may optionally be substituted one or more times with substituentsselected from the group consisting of halogen, alkyl, cycloalkyl,alkyloxy, cycloalkyloxy, phenyl or benzyl; or a group of the formula—CH₂C(═2 NOH)NH₂;

[0020] R² represents hydrogen; an alkyl group; a cycloalkyl group; agroup of the formula —CH₂CO₂R′, wherein R′ represents hydrogen or analkyl group; a phenyl or a benzyl group, which phenyl and benzyl groupsmay be substituted one or more times with substituents selected fromhalogen, —NO₂, —CN, —CF₃, alkyl, cycloalkyl, hydroxy, and alkoxy; and

[0021] R³, R⁴, R⁵, and R⁶ independently of each another representshydrogen; halogen; —NO₂; —CN; —CF₃; an alkyl group; an alkoxy group; aphenyl or a benzyl group, which phenyl and benzyl groups may besubstituted one or more times with substituents selected from halogen,—NO₂, —CN, —CF₃, alkyl, cycloalkyl, hydroxy, and alkoxy; or a group ofthe formula —SO₂NR″R′″, wherein R″ and R′″ independently of each anotherrepresents hydrogen or an alkyl group;

[0022] or R⁵ and R⁶ are as defined above, and R³ and R⁴ together form anadditional 4 to 7 membered fused ring, which fused ring may be aromatic,saturated or partially saturated, and which fused ring may optionally besubstituted one or more times with substituents selected from the groupconsisting of halogen, —NO₂, —CN, —CF₃, and a group of the formula—SO₂NR″R′″, wherein R″ and R′″ independently of each another representshydrogen or an alkyl group;

[0023] for the manufacture of a medicament for the treatment oralleviation of a disease or disorder or condition that is responsive toactivation of SK_(Ca) and/or lK_(Ca) channels.

[0024] In a second aspect, the invention provides novel isatinderivatives having the general formula

[0025] or a pharmaceutically acceptable salt or an oxide or a hydratethereof, wherein,

[0026] R¹ represents hydrogen; a C₁₋₆-alkyl group; a group of theformula —CH₂CO₂R′, wherein R′ represents hydrogen or C₁₋₃-alkyl; a groupof the formula —CH₂NH—Z, wherein Z represents phenyl or benzyl, whichphenyl and benzyl may optionally be substituted one or more times withhalogen; or a group of the formula —CH₂CO—Y, wherein Y represents aheterocyclic 6 membered monocyclic group containing at least onenitrogen atom as the heteroatom, and which heterocyclic group mayoptionally be substituted one or more times with a C₁₋₆-alkyl group or aphenyl group.

[0027] R² represents hydrogen; a C₁₋₆-alkyl group; a group of theformula —CH₂CO₂R′, wherein R′ represents hydrogen or an alkyl group; and

[0028] R³, R⁴, R⁵, and R⁶ independently of each another representshydrogen, halogen or a C₁₋₃-alkyl group;

[0029] or R⁵ and R⁶ are as defined above, and R³ and R⁴ together form anadditional 6 membered aromatic or heteroaromatic fused ring.

[0030] In a third aspect the invention provides pharmaceuticalcompositions comprising a therapeuticallly-effective amount of theisatin derivative of the invention, or a pharmaceutically-acceptableaddition salt thereof, together with at least onepharmaceutically-acceptable carrier or diluent.

[0031] In a fourth aspect, the invention provides a method for thetreatment or alleviation of a disease or disorder or condition of aliving animal body, including a human, which disorder or disease orcondition is responsive to activation of SK_(Ca) and/or lK_(Ca)channels, comprising the step of administering to such a living animalbody, including a human, in need thereof a therapeutically effectiveamount of a compound of the invention.

[0032] The compounds of the invention are particularly useful for thetreatment or alleviation of asthma, cystic fibrosis, chronic obstructivepulmonary disease and rhinorrhea, convulsions, vascular spasms, coronaryartery spasms, renal disorders, polycystic kidney disease, bladderspasms, urinary incontinence, bladder outflow obstruction, irritablebowel syndrome, gastrointestinal dysfunction, secretory diarrhoea,ischaemia, cerebral ischaemia, ischaemic hearth disease, anginapectoris, coronary hearth disease, traumatic brain injury, psychosis,anxiety, depression, dementia, memory and attention deficits,Alzheimer's disease, dysmenorrhea, narcolepsy, Reynaud's disease,intermittent claudication, Sjorgren's syndrome, migraine, arrhythmia,hypertension, absence seizures, myotonic muscle dystrophia, xerostomi,diabetes type II, hyperinsulinemia, premature labour, baldness, cancer,and immune-suppression.

DETAILED DISCLOSURE OF THE INVENTION

[0033] According to the present invention it has now been found that aparticular group of isatin derivatives possess valuable activity asopeners of SK_(Ca) and/or lK_(Ca) channels.

[0034] SK/IK Activating Agents

[0035] In the context of this invention, chemical compounds capable ofopening SK_(Ca) and/or IK_(Ca) channels are designated SK/IK channelactivating agents. The SK/IK channel activating agents of the inventionbelongs to a particular class of isatin derivatives (alternativelydesignated indole-2,3-dione-3-oxime derivatives), represented by thefollowing general formula

[0036] or a pharmaceutically acceptable salt or an oxide or a hydratethereof,

[0037] wherein,

[0038] R¹ represents hydrogen; an alkyl group; a cycloalkyl group; anacyl group; a phenyl or a benzyl group, which phenyl and benzyl groupsmay be substituted one or more times with substituents selected fromhalogen, —NO₂, —CN, —CF₃, alkyl, cycloalkyl, hydroxy, and alkoxy; agroup of the formula —CH₂CN; a group of the formula —CH₂CO₂R′, whereinR′ represents hydrogen or alkyl; a group of the formula—CH₂CONR^(IV)R^(V), wherein R^(IV) and R^(V) independently representshydrogen, alkyl, phenyl or benzyl, which phenyl and benzyl groups mayoptionally be substituted one or more times with halogen and/or alkyl,or R^(IV) and R^(V) together with the N-atom to which they are attachedform a heterocyclic 4 to 7 membered monocyclic group, which heterocyclicgroup may optionally be substituted one or more times with substituentsselected from the group consisting of halogen, alkyl, cycloalkyl,alkyloxy, cycloalkyloxy, phenyl or benzyl; or a group of the formula—CH₂C(═NOH)NH₂;

[0039] R² represents hydrogen; an alkyl group; a cycloalkyl group; agroup of the formula —CH₂CO₂R′, wherein R′ represents hydrogen or analkyl group; a phenyl or a benzyl group, which phenyl and benzyl groupsmay be substituted one or more times with substituents selected fromhalogen, —NO₂, —CN, —CF₃, alkyl, cycloalkyl, hydroxy, and alkoxy; and

[0040] R³, R⁴, R⁵, and R⁶ independently of each another representshydrogen; halogen; —NO₂; —CN; —CF₃; an alkyl group; an alkoxy group; aphenyl or a benzyl group, which phenyl and benzyl groups may besubstituted one or more times with substituents selected from halogen,—NO₂, —CN, —CF₃, alkyl, cycloalkyl, hydroxy, and alkoxy; or a group ofthe formula —SO₂NR″R′″, wherein R″ and R′″ independently of each anotherrepresents hydrogen or an alkyl group;

[0041] or R⁵ and R⁶ are as defined above, and R³ and R⁴ together form anadditional 4 to 7 membered fused ring, which fused ring may be aromatic,saturated or partially saturated, and which fused ring may optionally besubstituted one or more times with substituents selected from the groupconsisting of halogen, —NO₂, —CN, —CF₃, and a group of the formula—SO₂NR″R′″, wherein R″ and R′″ independently of each another representshydrogen or an alkyl group;

[0042] for the manufacture of a medicament for the treatment oralleviation of a disease or disorder or condition that is responsive toactivation of SK_(Ca) and/or IK_(Ca) channels.

[0043] In a preferred embodiment, R¹ of formula I represents hydrogen; aC₁₋₆-alkyl group; a phenyl group; a benzyl group; a group of the formula—CH₂CO₂R′, wherein R′ represents hydrogen or a C₁₋₆-alkyl group; a groupof the formula —CH₂NH-Z, wherein Z represents phenyl or benzyl, whichphenyl and benzyl may optionally be substituted one or more times withhalogen; or a group of the formula —CH₂CO—Y, wherein Y represents aheterocyclic 6 membered monocyclic group containing at least onenitrogen atom as the heteroatom, and which heterocyclic group mayoptionally be substituted one or more times with a C₁₋₆-alkyl group or aphenyl group. Y preferably represents a piperidinyl or a piperazinylgroup.

[0044] In another embodiment, R² of formula I represents hydrogen,C₁₋₆-alkyl, phenyl, benzyl, or a group of the formula —CH₂COOH.

[0045] In a third embodiment, R³, R⁴, R⁵ and R⁶ of formula Iindependently of each another represents hydrogen, F, Br, Cl, NO₂, CN,CF₃, or C₁₋₆-alkyl.

[0046] In a fifth embodiment, the isatin derivative for use according tothe invention is represented by the general formula

[0047] or a pharmaceutically acceptable salt or an oxide or a hydratethereof,

[0048] wherein,

[0049] R¹, R², R⁵ and R⁶ are as defined above; and

[0050] X represents a substituent selected from the group consisting ofhydrogen, halogen, —NO₂, —CN, —CF₃, and a group of the formula—SO₂NR″R′″, wherein R″ and R′″ independently of each another representshydrogen or an alkyl group.

[0051] In a most preferred embodiment, the isatin derivative for useaccording to the invention is

[0052] 5,7-dinitro-1-methyl-1 H-indole-2,3-dione-3-(O-methyloxime);

[0053] 5-bromo-7-nitro-1 H-indole-2,3-dione-3-oxime;

[0054] 5,7-dinitro-1-methyl-1 H-indole-2,3-dione-3-oxime;

[0055] 5-nitro-1 H-benzi[g]indole-2,3-dione-3-oxime;

[0056] 5-nitro-1 H-6,7,8,9-tetrahydro-benz[g]indole-2,3-dione-3-oxime;

[0057] 5,7-dinitro-1-methyl-1 H-indole-2,3-dione-3-(O-methyloxime);

[0058] 5,7-dinitro-1 H-indole-2,3-dione-3-(O-methyloxime);

[0059] 5,7-dinitro-1-ethyl-1 H-indole-2,3-dione-3-(O-methyloxime);

[0060] 5-nitro-3-(O-methyloxime)-1 H-indole-2,3-dione;

[0061] 1-phenyl-1 H-indole-2,3-dione-3-(O-methyloxime);

[0062] 1 H-indole-2,3-dione-3-(O-methyloxime);

[0063] 5,7-dibromo-1-methyl-1 H-indole-2,3-dione-3-(O-methyloxime);

[0064] 5,7-dibromo-1 H-indole-2,3-dione-3-(O-methyloxime);

[0065] 1-methyl-5-nitro-1 H-indole-2,3-dione-3-(O-methyloxime);

[0066] 5,6-dichloro-1-methyl-1 H-indole-2,3-dione-3-(O-methyloxime);

[0067] 4,5-dichloro-1-methyl-1 H-indole-2,3-dione-3-(O-methyloxime);

[0068] 5,7-dinitro-1-benzyl-1 H-indole-2,3-dione-3-(O-methyloxime);

[0069] 4,6-ditrifluoromethyl-1-methyl-1H-indole-2,3-dione-3-(O-methyloxime);

[0070] 5-nitro-7-trifluoromethyl-1-methyl-1H-indole-2,3-dione-3-(O-methyloxime);

[0071] 5-nitro-7-trifluoromethyl-1 H-indole-2,3-dione-3-(O-methyloxime);

[0072] 5,7-dinitro-6-methoxy-1-methyl-1H-indole-2,3-dione-3-(O-methyloxime);

[0073] 5,7-dinitro-1-(O-ethylcarboxymethyl)-1H-indole-2,3-dione-3-(O-methyloxime);

[0074] 5-nitro-1-methyl-1 H-benz[g]indole-2,3-dione-3-(O-methyloxime);

[0075] 5-bromo-1-ethoxycarbonylmethyl)-1H-indole-2,3-dione-3-(O-methyloxime);

[0076] 5,7-dibromo-1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione-3-(O-methyloxime);

[0077] 5-methyl-1-(methoxycarbonylmethyl)-1H-indole-2,3-dione-3-(O-ethyioxime);

[0078] 5-nitro-1-methyl-1H-6,7,8,9-tetrahydro-benz[g]-indole-2,3-dione-3-(O-methyloxime);

[0079] 1 H-benz[g]indole-2,3-dione-3-oxime;

[0080] 5,7-dinitro-1-methyl-1 H-indole-2,3-dione-3-oxime;

[0081] 5,7-dibromo- 1 H-indole-2,3-dione-3-oxime;

[0082] 5-bromo-1-methyl-1 H-indole-2,3-dione-3-oxime;

[0083] 5,7-dinitro-1 H-indole-2,3-dione-3-oxime;

[0084] 5-bromo-7-nitro-1 H-indole-2,3-dione-3-oxime;

[0085] 5-bromo-1 H-indole-2,3-dione-3-oxime;

[0086] 5-nitro-1 H-indole-2,3-dione-3-oxime;

[0087] 5-methyl-1 H-indole-2,3-dione-3-oxime;

[0088] 1 H-indole-2,3-dione-3-oxime;

[0089] 1-methyl-6,7,8,9-tetrahydro-1 H-benz[g]indole-2,3-dione-3-oxime;

[0090] 5,6-dichloro-1-methyl-1 H-indole-2,3-dione-3-oxime;

[0091] 4-phenyl-7-methoxy-1 H-indole-2,3-dione-3-oxime;

[0092] 4,5-dichloro-1 H-indole-2,3-dione-3-oxime;

[0093] 1-phenyl-1 H-indole-2,3-dione-3-oxime;

[0094] 4,5-dichloro-1-methyl-1 H-indole-2,3-dione-3-oxime;

[0095] 5-nitro-1 H-benz[g]indole-2,3-dione-3-oxime;

[0096] 5-nitro-7-trifluoromethyl-1-methyl-1 H-indole-2,3-dione-3-oxime;

[0097] 5-nitro-7-trifluorimethyl-1 H-indole-2,3-dione-3-oxime;

[0098] 5-nitro-1 H-6,7,8,9-tetrahydro-benz[g]indole-2,3-dione-3-oxime;

[0099] 5-fluoro-7-nitro-1 H-indole-2,3-dione-3-oxime;

[0100] 5,7-dinitro-1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione-3-oxime;

[0101] 1-(ethoxycarbonylmethyl)-1 H-indole-2,3-dione-3-oxime;

[0102] 5-bromo-1-(ethoxycarbonylmethyl)-1 H-indole-2,3-dione-3-oxime;

[0103] 5,7-dinitro-1 H-indole-2,3-dione-3-oxime;

[0104] 5,7-dinitro-1 H-indole-2,3-dione-3-(O-benzyloxime);

[0105] 5,7-dinitro-1 H-1-benzyl-indole-2,3-dione-3-(O-benzyloxime);

[0106] 5,7-dinitro-1-methyl-1 H-indole-2,3-dione-3-(Obenzyloxime);

[0107] 5,7-dinitro-1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione-3-(O-enzyloxime);

[0108] 5-nitro-1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione-3-(O-benzyloxime);

[0109] 1-methoxy-1 H-indole-2,3-dione-3-oxime;

[0110] 1-acetyl-5-bromo-1 H-indole-2,3-dione;

[0111] 1-hydroxy-1-H-indole-2,3-dione-3-oxime;

[0112] 5-bromoisatin 3-oxime;

[0113] 5,6-dichloro-1-methylisatin 3-oxime;

[0114] 4,5-dichloroisatin 3-oxime;

[0115] 4,5-dichloro-1-methylisatin 3-oxime;

[0116] O-methyl-4,5-dichloro-1-methylisatin 3-oxime;

[0117] benz[e]isatin 3-oxime;

[0118] 6,7-dichloroisatin 3-oxime;

[0119] O-methyl 6,7-dichloroisatin 3-oxime;

[0120] O-methyl 6,7-dichloro-1-methylisatin 3-oxime;

[0121] 6,7-dichloro-1-methylisatin 3-oxime;

[0122] potassium 2-(6,7-dichloroisatin-1-yl 3-oxime)acetate;

[0123] O-t-butyl 6,7-dichloroisatin 3-oxime;

[0124] O-((4-phenyipiperazin-1-yl)carbonylmethyl) 6,7-dichloroisatin3-oxime;

[0125] O-(4-chlorobenzylamino)methyl 6,7-dichloroisatin 3-oxime;

[0126] 6,7-difluoroisatin 3-oxime;

[0127] 6,7-dimethylisatin 3-oxime;

[0128] 5,6-dichloroisatin 3-oxime;

[0129] O-carboxymethyl 5-bromoisatin 3-oxime;

[0130] O-(ethoxycarbonylmethyl) 5-bromoisatin 3-oxime;

[0131] O-(carboxymethyl) 6,7-dichloroisatin 3-oxime;

[0132] O-chloro-7-methylisatin 3-oxime;

[0133] 6-fluoro-7-methylisatin 3-oxime; or

[0134] 6-fluoro-7-methoxyisatin 3-oxime;

[0135] or a pharmaceutically acceptable salt or an oxide or a hydratethereof.

[0136] Chemical compounds of formula (I) have been described and may beprepared by methods known in the art, e.g. as disclosed in EP 432,648.

[0137] Novel Isatin Derivatives

[0138] In another aspect the invention provides novel isatin derivativesrepresented by the general formula

[0139] or a pharmaceutically acceptable salt or an oxide or a hydratethereof,

[0140] wherein,

[0141] R¹ represents hydrogen, a C₁₋₆-alkyl group; a group of theformula —CH₂CO₂R′, wherein R′ represents hydrogen or C₁₋₃-alkyl; a groupof the formula —CH₂NH-Z, wherein Z represents phenyl or benzyl, whichphenyl and benzyl may optionally be substituted one or more times withhalogen; or a group of the formula —CH₂CO—Y, wherein Y represents aheterocyclic 6 membered monocyclic group containing at least onenitrogen atom as the heteroatom, and which heterocyclic group mayoptionally be substituted one or more times with a C₁₋₆-alkyl group or aphenyl group;

[0142] R² represents hydrogen; a C₁₋₆-alkyl group; a group of theformula —CH₂CO₂R′, wherein R′ represents hydrogen or an alkyl group; and

[0143] R³, R⁴, R⁵, and R⁶ independently of each another representshydrogen, halogen or a C₁₋₃-alkyl group;

[0144] or R⁵ and R⁶ are as defined above, and R³ and R⁴ together form anadditional 6 membered aromatic or heteroaromatic fused ring

[0145] In a most preferred embodiment, the novel isatin derivative ofthe invention is

[0146] 5-bromoisatin 3-oxime;

[0147] 5,6-dichloro-1-methylisatin 3-oxime;

[0148] 4,5-dichloroisatin 3-oxime;

[0149] 4,5-dichloro-1-methylisatin 3-oxime;

[0150] O-methyl-4,5-dichloro-1-methylisatin 3-oxime;

[0151] benz[e]isatin 3-oxime;

[0152] 6,7-dichloroisatin 3-oxime;

[0153] O-methyl 6,7-dichloroisatin 3-oxime;

[0154] O-methyl 6,7-dichloro-1-methylisatin 3-oxime;

[0155] 6,7-dichloro-1-methylisatin 3-oxime;

[0156] potassium 2-(6,7-dichloroisatin-1-yl 3-oxime)acetate;

[0157] O-t-butyl 6,7-dichloroisatin 3-oxime;

[0158] O-((4-phenylpiperazin-1-yl)carbonylmethyl) 6,7-dichloroisatin3-oxime;

[0159] O-(4-chlorobenzylamino)methyl 6,7-dichloroisatin 3-oxime;

[0160] 6,7-difluoroisatin 3-oxime;

[0161] 6,7-dimethylisatin 3-oxime;

[0162] 5,6-dichloroisatin 3-oxime;

[0163] O-carboxymethyl 5-bromoisatin 3-oxime;

[0164] O-(ethoxycarbonylmethyl) 5-bromoisatin 3-oxime;

[0165] O-(carboxymethyl) 6,7-dichloroisatin 3-oxime;

[0166] 6-chloro-7-methylisatin 3-oxime;

[0167] 6-fluoro-7-methylisatin 3-oxime; or

[0168] 6-fluoro-7-methoxyisatin 3-oxime;

[0169] or a pharmaceutically acceptable salt or an oxide or a hydratethereof.

[0170] The novel isatin derivatives of the invention may be prepared bythe skilled person by conventional methods, using commercially availablestarting materials. In a preferred embodiment, the isatin derivatives ofthe invention are prepared using the methods described in the workingexamples below.

[0171] Definition of Substituents

[0172] In the context of this invention halogen represents a fluorine, achlorine, a bromine or a iodine atom.

[0173] In the context of this invention an alkyl group designates aunivalent saturated, straight or branched hydrocarbon chain. Thehydrocarbon chain preferably contain of from one to twelve carbon atoms(C₁₋₁₂-alkyl), more preferred of from one to six carbon atoms(C₁₋₆-alkyl; lower alkyl), including pentyl, isopentyl, neopentyl,tertiary pentyl, hexyl and isohexyl. In a preferred embodiment alkylrepresents a C₁₋₄-alkyl group, including butyl, isobutyl, secondarybutyl, and tertiary butyl. In a most preferred embodiment alkylrepresents a C₁₋₃-alkyl group, which may in particular be methyl, ethyl,propyl or isopropyl.

[0174] In the context of this invention a cycloalkyl group designates acyclic alkyl group, preferably containing of from three to seven carbonatoms (C₃₋₇-cycloalkyl), including cyclopropyl, cyclobutyl, cyclopentyl,and cyclohexyl.

[0175] In the context of this invention an alkoxy group designates an“alkyl-O—” group, wherein alkyl is as defined above.

[0176] In the context of this invention an acyl group designates acarboxy group or an alkylcarbonyl group, wherein alkyl is as definedabove. Examples of preferred acyl groups of the invention are carboxy,acetyl, and propionyl.

[0177] In the context of this invention a mono-heterocyclic group is amonocyclic compound, which holds one or more heteroatoms in its ringstructure. Preferred heteroatoms include nitrogen (N), oxygen (O), andsulphur (S). One or more of the ring structures may in particular bearomatic (i.e. a heteroaryl or heteroaromatic group), saturated orpartially saturated. Preferred heterocyclic monocyclic groups of theinvention include 5- and 6 membered heterocyclic monocyclic groups.

[0178] Examples of preferred saturated or partially saturatedheterocyclic monocyclic groups of the invention include1,3,5,6,2-dioxadiazinyl, 1,2,3,4,5-,1,2,3,5,4-dioxadiazolyl, dioxanyl,1,3-dioxolyl, 1,3,5,6,2-dithiadiazinyl, 1,2,3,4,5- or1,2,3,5,4-dithiadiazolyl, 2-isoimidazolyl, isopyrrolyl, isotetrazolyl,1,2,3- or 1,2,4-isotriazolyl, morpholinyl, oxadiazinyl, 1,2,4-, 1,2,6-,1,3,2-, 1,3,6- or 1,4,2-oxazinyl, piperazinyl, homopiperazinyl,piperidinyl, 1,2-, 1,3- or 1,4-pyranyl, and 1,2,3-pyrrolidinyl. Mostpreferred heterocyclic 6 membered monocyclic groups of the invention arepiperidinyl an piperazinyl.

[0179] Examples of preferred aromatic heterocyclic monocyclic groups ofthe invention include 1,3,2,4- or 1,3,4,5-dioxadiazolyl, dioxatriazinyl,dioxazinyl, 1,2,3-,1,2,4-, 1,3,4- or 1,3,4-dioxazolyl, 1,3,2,4- or1,3,4,5-dithiadiazolyl, dithiatriazinyl, dithiazinyl, 1,2,3-dithiazolyl,2- or 3-furanyl, furazanyl, 1,2 or 4-imidazolyl, isoindazolyl,isothiazol-3,4 or 5-yl, isoxazol-3,4 or 5-yl, 1,2,3-, 1,2,4-, 1,2,5- or1,3,4-oxadiazol-3,4 or 5-yl, oxatetrazinyl, oxatriazinyl, 1,2,3,4- or1,2,3,5-oxatriazolyl, oxazol-2,4 or 5-yl, 2 or 3-pyrazinyl, 1,3 or4-pyrazolyl, 3 or 4-pyridazinyl, 2,3 or 4-pyridinyl, 2,4 or5-pyrimidinyl, 1,2 or 3-pyrrolyl (azolyl), 1,2,3,4- or2,1,3,4-tetrazolyl, thiadiazol-3,4 or 5-yl, thiazol-2,4 or 5-yl, 2 or3-thienyl, 1,2,3-, 1,2,4- or 1,3,5-triazinyl, and 1,2,3-, 1,2,4-, 2,1,3-or 4,1,2-triazolyl. Most preferred heterocyclic 6 membered monocyclicgroups of the invention are 1-, 2- or 3-pyridinyl, 2,4,5 or6-pyrimidinyl, and 2,3,5 or 6-pyrazinyl.

[0180] Pharmaceutically Acceptable Salts

[0181] The SK/IK channel activating agents of the invention may beprovided in any form suitable for the intended administration. Suitableforms include pharmaceutically (i.e. physiologically) acceptable salts,and pre- or prodrug forms of the chemical compound of the invention.

[0182] Examples of pharmaceutically acceptable addition salts include,without limitation, the non-toxic inorganic and organic acid additionsalts such as the acetate derived from acetic acid, the aconate derivedfrom aconitic acid, the ascorbate derived from ascorbic acid, thebenzenesulfonate derived from benzensulfonic acid, the benzoate derivedfrom benzoic acid, the cinnamate derived from cinnamic acid, the citratederived from citric acid, the embonate derived from embonic acid, theenantate derived from enanthic acid, the formate derived from formicacid, the fumarate derived from fumaric acid, the glutamate derived fromglutamic acid, the glycolate derived from glycolic acid, thehydrochloride derived from hydrochloric acid, the hydrobromide derivedfrom hydrobromic acid, the lactate derived from lactic acid, the maleatederived from maleic acid, the malonate derived from malonic acid, themandelate derived from mandelic acid, the methanesulfonate derived frommethane sulphonic acid, the naphthalene-2-sulphonate derived fromnaphtalene-2-sulphonic acid, the nitrate derived from nitric acid, theperchlorate derived from perchloric acid, the phosphate derived fromphosphoric acid, the phthalate derived from phthalic acid, thesalicylate derived from salicylic acid, the sorbate derived from sorbicacid, the stearate derived from stearic acid, the succinate derived fromsuccinic acid, the sulphate derived from sulphuric acid, the tartratederived from tartaric acid, the toluene-p-sulphonate derived fromp-toluene sulphonic acid, and the like. Such salts may be formed byprocedures well known and described in the art.

[0183] Other acids such as oxalic acid, which may not be consideredpharmaceutically acceptable, may be useful in the preparation of saltsuseful as intermediates in obtaining a chemical compound of theinvention and its pharmaceutically acceptable acid addition salt.

[0184] Metal salts of a chemical compound of the invention includesalkali metal salts, such as the sodium salt of a chemical compound ofthe invention containing a carboxy group.

[0185] The chemical compound of the invention may be provided inunsolved or solvated forms together with a pharmaceutically acceptablesolvents such as water, ethanol, and the like. Solvated forms may alsoinclude hydrated forms such as the monohydrate, the dihydrate, thehemihydrate, the trihydrate, the tetrahydrate, and the like. In general,solvated forms are considered equivalent to unsolved forms for thepurposes of this invention.

[0186] Steric Isomers

[0187] The SK/IK channel activating agents of the present invention mayexist in (+) and (−) forms as well as in racemic forms. The racemates ofthese isomers and the individual isomers themselves are within the scopeof the present invention.

[0188] Racemic forms can be resolved into the optical antipodes by knownmethods and techniques. One way of separating the diastereomeric saltsis by use of an optically active acid, and liberating the opticallyactive amine compound by treatment with a base. Another method forresolving racemates into the optical antipodes is based uponchromatography on an optical active matrix. Racemic compounds of thepresent invention can thus be resolved into their optical antipodes,e.g., by fractional crystallisation of d- or l- (tartrates, mandelates,or camphorsulphonate) salts for example.

[0189] The chemical compounds of the present invention may also beresolved by the formation of diastereomeric amides by reaction of thechemical compounds of the present invention with an optically activeactivated carboxylic acid such as that derived from (+) or (−)phenylalanine, (+) or (−) phenylglycine, (+) or (−) camphanic acid or bythe formation of diastereomeric carbamates by reaction of the chemicalcompound of the present invention with an optically active chloroformateor the like.

[0190] Additional methods for the resolving the optical isomers areknown in the art. Such methods include those described by Jaques J,Collet A, & Wilen S in “Enantiomers Racemates, and Resolutions”, JohnWiley and Sons, New York (1981).

[0191] Moreover, some of the chemical compounds of the invention beingoximes, may thus exist in two forms, syn- and anti-form (Z- and E-form),depending on the arrangement of the substituents around the —C═N— doublebond. A chemical compound of the present invention may thus be the syn-or the anti-form (Z- and E-form), or it may be a mixture hereof.

[0192] Biological Activity

[0193] According to the present invention it has now been found that theisatin derivatives of the invention possess valuable activity as openersof SK_(Ca) and/or IK_(Ca) channels.

[0194] The SK/IK channel activating activity may be monitored usingconventional electrophysiological methods such as patch-clamptechniques, or conventional spectroscopic methods such as FLIPR assay(Fluorescence Image Plate Reader; available from Molecular Devices).These methods generally comprises subjecting an SK_(Ca) or IK_(Ca)containing cell to the action of the chemical compound of the invention,followed by monitoring the membrane potential of the SK_(Ca) or lK_(Ca)containing cell in order to identify changes in the membrane potentialcaused by the action of the compound of the invention.

[0195] In Example 5 the biological activity of the compounds of theinvention is demonstrated using electrophysiologic patch-clamptechniques.

[0196] Based on their biological activity the compounds of the inventionare considered useful for the treatment or alleviation of diseases orconditions responsive to activation of SK_(Ca) and/or IK_(Ca) channels,including diseases or conditions like respiratory diseases such asasthma, cystic fibrosis, chronic obstructive pulmonary disease andrhinorrhea, convulsions, vascular spasms, coronary artery spasms, renaldisorders, polycystic kidney disease, bladder spasms, urinaryincontinence, bladder outflow obstruction, irritable bowel syndrome,gastrointestinal dysfunction, secretory diarrhoea, ischaemia, cerebralischaemia, ischaemic hearth disease, angina pectoris, coronary hearthdisease, traumatic brain injury, psychosis, anxiety, depression,dementia, memory and attention deficits, Alzheimer's disease,dysmenorrhea, narcolepsy, Reynaud's disease, intermittent claudication,Sjorgren's syndrome, migraine, arrhythmia, hypertension, absenceseizures, myotonic muscle dystrophia, xerostomi, diabetes type II,hyperinsulinemia, premature labour, baldness, cancer, and immunesuppression.

[0197] The compounds of the invention is considered particularly usefulfor reducing or inhibiting undesired immunoregulatory actions. In apreferred embodiment, therefore, the compounds of the may be used in thetreatment or alleviation of a diseases, disorders or condition relatedto immune dysfunction, or in order to obtain immune suppression in anindividual in need herefore.

[0198] In another, and still more preferred embodiment, the inventionrelates to the use of a compound of the invention in a combinationtherapy with known immune-suppressants for the treatment or alleviationof a diseases, disorders or condition related to immune dysfunction, orfor obtaining immune suppression. Preferred immune-suppressants tocombine with the compounds of the invention include the calcineurininhibitors (i.e. protein phosphatase 2B inhibitors), in particularCyclosporin, and FK506.

[0199] Conditions which may benefit from this treatment include, but arenot limited to diseases, disorders or conditions such as autoimmunediseases, e.g. Addison's disease, alopecia areata, Ankylosingspondylitis, hemolytic anemia (anemia haemolytica), pernicious anemia(anemia perniciosa), aphthae, aphthous stomatitis, arthritis,arteriosclerotic disorders, osteoarthritis, rheumatoid arthritis,aspermiogenese, asthma bronchiale, autoimmune asthma, autoimmunehemolysis, Bechet's disease, Boeck's disease, inflammatory boweldisease, Burkitt's lymphoma, Chron's disease, chorioiditis, colitisulcerosa, Coeliac disease, cryoglobulinemia, dermatitis herpetiformis,dermatomyositis, insulin-dependent type I diabetes, juvenile diabetes,idiopathic diabetes insipidus, insulin-dependent diabetes mellisis,autoimmune demyelinating diseases, Dupuytren's contracture,encephalomyelitis, encephalomyelitis allergica, endophthalmiaphacoanaphylactica, enteritis allergica, autoimmune enteropathysyndrome, erythema nodosum leprosum, idiopathic facial paralysis,chronic fatigue syndrome, febris rheumatica, glomerulo nephritis,Goodpasture's syndrome, Graves' disease, Hamman-Rich's disease,Hashimoto's disease, Hashimoto's thyroiditis, sudden hearing loss,sensoneural hearing loss, hepatitis chronica, Hodgkin's disease,haemoglobinuria paroxysmatica, hypogonadism, ileitis regionalis, iritis,leucopenia, leucemia, lupus erythematosus disseminatus, systemic lupuserythematosus, cutaneous lupus erythematosus, lymphogranuloma malignum,mononucleosis infectiosa, myasthenia gravis, traverse myelitis, primaryidiopathic myxedema, nephrosis, ophthalmia symphatica, orchitisgranulomatosa, pancreatitis, pemphigus, pemphigus vulgaris,polyarteritis nodosa, polyarthritis chronica primaria, polymyositis,polyradiculitis acuta, psoreasis, purpura, pyoderma gangrenosum,Quervain's thyreoiditis, Reiter's syndrome, sarcoidosis, ataxicsclerosis, progressive systemic sclerosis, scleritis, scierodermia,multiple sclerosis, sclerosis disseminate, acquired spenic atrophy,infertility due to antispermatozoan antobodies, thrombocytopenia,idiopathic thrombocytopenia purpura, thymoma, acute anterior uveitis,vitiligo, AIDS, HIV, SCID and Epstein Barr virus associated diseasessuch as Sjorgren's syndrome, virus (AIDS or EBV) associated B celllymphoma, parasitic diseases such as Lesihmania, and immunosuppresseddisease states such as viral infections following allografttransplantations, graft vs. Host syndrome, transplant rejection, orAIDS, cancers, chronic active hepatitis diabetes, toxic chock syndrome,food poisoning, and transplant rejection.

[0200] Pharmaceutical Compositions

[0201] In another aspect the invention provides novel pharmaceuticalcompositions comprising a therapeutically effective amount of a chemicalcompound having SK_(Ca) or IK_(Ca) activating activity.

[0202] While a chemical compound of the invention for use in therapy maybe administered in the form of the raw chemical compound, it ispreferred to introduce the active ingredient, optionally in the form ofa physiologically acceptable salt, in a pharmaceutical compositiontogether with one or more adjuvants, excipients, carriers, buffers,diluents, and/or other customary pharmaceutical auxiliaries.

[0203] In a preferred embodiment, the invention provides pharmaceuticalcompositions comprising the SK/IK channel activating agents of theinvention, or a pharmaceutically acceptable salt or derivative thereof,together with one or more pharmaceutically acceptable carriers therefor,and, optionally, other therapeutic and/or prophylactic ingredients, knowand used in the art. The carrier(s) must be “acceptable” in the sense ofbeing compatible with the other ingredients of the formulation and notharmful to the recipient thereof.

[0204] Pharmaceutical compositions of the invention may be thosesuitable for oral, rectal, bronchial, nasal, topical (including buccaland sub-lingual), transdermal, vaginal or parenteral (includingcutaneous, subcutaneous, intramuscular, and intravenous injection)administration, or those in a form suitable for administration byinhalation or insufflation.

[0205] The chemical compound of the invention, together with aconventional adjuvant, carrier, or diluent, may thus be placed into theform of pharmaceutical compositions and unit dosages thereof. Such formsinclude solids, and in particular tablets, filled capsules, powder andpellet forms, and liquids, in particular aqueous or non-aqueoussolutions, suspensions, emulsions, elixirs, and capsules filled with thesame, all for oral use, suppositories for rectal administration, andsterile injectable solutions for parenteral use. Such pharmaceuticalcompositions and unit dosage forms thereof may comprise conventionalingredients in conventional proportions, with or without additionalactive compounds or principles, and such unit dosage forms may containany suitable effective amount of the active ingredient commensurate withthe intended daily dosage range to be employed.

[0206] The chemical compound of the present invention can beadministered in a wide variety of oral and parenteral dosage forms. Itwill be obvious to those skilled in the art that the following dosageforms may comprise, as the active component, either a chemical compoundof the invention or a pharmaceutically acceptable salt of a chemicalcompound of the invention.

[0207] For preparing pharmaceutical compositions from a chemicalcompound of the present invention, pharmaceutically acceptable carrierscan be either solid or liquid. Solid form preparations include powders,tablets, pills, capsules, cachets, suppositories, and dispersiblegranules. A solid carrier can be one or more substances which may alsoact as diluents, flavouring agents, solubilizers, lubricants, suspendingagents, binders, preservatives, tablet disintegrating agents, or anencapsulating-material.

[0208] In powders, the carrier is a finely divided solid which is in amixture with the finely divided active component.

[0209] In tablets, the active component is mixed with the carrier havingthe necessary binding capacity in suitable proportions and compacted inthe shape and size desired.

[0210] The powders and tablets preferably contain from five or ten toabout seventy percent of the active compound. Suitable carriers aremagnesium carbonate, magnesium stearate, talc, sugar, lactose, pectin,dextrin, starch, gelatin, tragacanth, methylcellulose, sodiumcarboxymethylcellulose, a low melting wax, cocoa butter, and the like.The term “preparation” is intended to include the formulation of theactive compound with encapsulating material as carrier providing acapsule in which the active component, with or without carriers, issurrounded by a carrier, which is thus in association with it.Similarly, cachets and lozenges are included. Tablets, powders,capsules, pills, cachets, and lozenges can be used as solid formssuitable for oral administration.

[0211] For preparing suppositories, a low melting wax, such as a mixtureof fatty acid glyceride or cocoa butter, is first melted and the activecomponent is dispersed homogeneously therein, as by stirring. The moltenhomogenous mixture is then poured into convenient sized moulds, allowedto cool, and thereby to solidify.

[0212] Compositions suitable for vaginal administration may be presentedas pessaries, tampons, creams, gels, pastes, foams or sprays containingin addition to the active ingredient such carriers as are known in theart to be appropriate.

[0213] Liquid preparations include solutions, suspensions, andemulsions, for example, water or water-propylene glycol solutions. Forexample, parenteral injection liquid preparations can be formulated assolutions in aqueous polyethylene glycol solution.

[0214] The chemical compound according to the present invention may thusbe formulated for parenteral administration (e.g. by injection, forexample bolus injection or continuous infusion) and may be presented inunit dose form in ampoules, pre-filled syringes, small volume infusionor in multi-dose containers with an added preservative. The compositionsmay take such forms as suspensions, solutions, or emulsions in oily oraqueous vehicles, and may contain formulation agents such as suspending,stabilising and/or dispersing agents. Alternatively, the activeingredient may be in powder form, obtained by aseptic isolation ofsterile solid or by lyophilization from solution, for constitution witha suitable vehicle, e.g. sterile, pyrogen-free water, before use.

[0215] Aqueous solutions suitable for oral use can be prepared bydissolving the active component in water and adding suitable colorants,flavours, stabilising and thickening agents, as desired.

[0216] Aqueous suspensions suitable for oral use can be made bydispersing the finely divided active component in water with viscousmaterial, such as natural or synthetic gums, resins, methylcellulose,sodium carboxymethylcellulose, or other well known suspending agents.

[0217] Also included are solid form preparations which are intended tobe converted, shortly before use, to liquid form preparations for oraladministration. Such liquid forms include solutions, suspensions, andemulsions. These preparations may contain, in addition to the activecomponent, colorants, flavours, stabilisers, buffers, artificial andnatural sweeteners, dispersants, thickeners, solubilizing agents, andthe like.

[0218] For topical administration to the epidermis the chemical compoundaccording to the invention may be formulated as ointments, creams orlotions, or as a transdermal patch. Ointments and creams may, forexample, be formulated with an aqueous or oily base with the addition ofsuitable thickening and/or gelling agents. Lotions may be formulatedwith an aqueous or oily base and will in general also contain one ormore emulsifying agents, stabilising agents, dispersing agents,suspending agents, thickening agents, or colouring agents.

[0219] Compositions suitable for topical administration in the mouthinclude lozenges comprising the active agent in a flavoured base,usually sucrose and acacia or tragacanth; pastilles comprising theactive ingredient in an inert base such as gelatin and glycerine orsucrose and acacia; and mouthwashes comprising the active ingredient ina suitable liquid carrier.

[0220] Solutions or suspensions are applied directly to the nasal cavityby conventional means, for example with a dropper, pipette or spray. Thecompositions may be provided in single or multi-dose form. In the lattercase of a dropper or pipette, this may be achieved by the patientadministering an appropriate, predetermined volume of the solution orsuspension. In the case of a spray, this may be achieved for example bymeans of a metering atomising spray pump.

[0221] Administration to the respiratory tract may also be achieved bymeans of an aerosol formulation in which the active ingredient isprovided in a pressurised pack with a suitable propellant such as achlorofluorocarbon (CFC) for example dichlorodifluoromethane,trichlorofluoromethane, or dichlorotetrafluoroethane, carbon dioxide, orother suitable gas. The aerosol may conveniently also contain asurfactant such as lecithin. The dose of drug may be controlled byprovision of a metered valve.

[0222] Alternatively the active ingredients may be provided in the formof a dry powder, for example a powder mix of the compound in a suitablepowder base such as lactose, starch, starch derivatives such ashydroxypropylmethyl cellulose and polyvinylpyrrolidone (PVP).Conveniently the powder carrier will form a gel in the nasal cavity. Thepowder composition may be presented in unit dose form for example incapsules or cartridges of, e.g., gelatin, or blister packs from whichthe powder may be administered by means of an inhaler.

[0223] In compositions intended for administration to the respiratorytract, including intranasal compositions, the compound will generallyhave a small particle size for example of the order of 5 microns orless. Such a particle size may be obtained by means known in the art,for example by micronization.

[0224] When desired, compositions adapted to give sustained release ofthe active ingredient may be employed.

[0225] The pharmaceutical preparations are preferably in unit dosageforms. In such form, the preparation is subdivided into unit dosescontaining appropriate quantities of the active component. The unitdosage form can be a packaged preparation, the package containingdiscrete quantities of preparation, such as packaged tablets, capsules,and powders in vials or ampoules. Also, the unit dosage form can be acapsule, tablet, cachet, or lozenge itself, or it can be the appropriatenumber of any of these in packaged form.

[0226] Tablets or capsules for oral administration and liquids forintravenous administration and continuous infusion are preferredcompositions.

[0227] Further details on techniques for formulation and administrationmay be found in the latest edition of Remington's PharmaceuticalSciences (Maack Publishing Co., Easton, Pa.).

[0228] A therapeutically effective dose refers to that amount of activeingredient which ameliorates the symptoms or condition. Therapeuticefficacy and toxicity, e.g. ED₅₀ and LD₅₀, may be determined by standardpharmacological procedures in cell cultures or experimental animals. Thedose ratio between therapeutic and toxic effects is the therapeuticindex and may be expressed by the ratio LD₅₀/ED₅₀. Pharmaceuticalcompositions which exhibit large therapeutic indexes are preferred.

[0229] The dose administered must of course be carefully adjusted to theage, weight and condition of the individual being treated, as well asthe route of administration, dosage form and regimen, and the resultdesired, and the exact dosage should of course be determined by thepractitioner.

[0230] The actual dosage depend on the nature and severity of thedisease being treated, and is within the discretion of the physician,and may be varied by titration of the dosage to the particularcircumstances of this invention to produce the desired therapeuticeffect. However, it is presently contemplated that pharmaceuticalcompositions containing of from about 0.1 to about 500 mg of activeingredient per individual dose, preferably of from about 1 to about 100mg, most preferred of from about 1 to about 10 mg, are suitable fortherapeutic treatments.

[0231] The active ingredient may be administered in one or several dosesper day. A satisfactory result can, in certain instances, be obtained ata dosage as low as 0.1 μg/kg i.v. and 1 μg/kg p.o. The upper limit ofthe dosage range is presently considered o be about 10 mg/kg i.v. and100 mg/kg p.o. Preferred ranges are from about 0.1 μg/kg to about 10mg/kg/day i.v., and from about 1 μg/kg to about 100 mg/kg/day p.o.

[0232] Methods of Theraphy

[0233] In another aspect the invention provides a method for thetreatment or alleviation of a disease or disorder or condition of aliving animal body, including a human, which disorder or disease orcondition is responsive to activation of SK_(Ca) and/or IK_(Ca)channels, comprising the step of administering to such a living animalbody, including a human, in need thereof a therapeutically effectiveamount of a compound of the invention.

[0234] In a preferred embodiment, the disease or disorder or conditionis a respiratory disease such as asthma, cystic fibrosis, chronicobstructive pulmonary disease and rhinorrhea, convulsions, vascularspasms, coronary artery spasms, renal disorders, polycystic kidneydisease, bladder spasms, urinary incontinence, bladder outflowobstruction, irritable bowel syndrome, gastrointestinal dysfunction,secretory diarrhoea, ischaemia, cerebral ischaemia, ischaemic hearthdisease, angina pectoris, coronary hearth disease, traumatic braininjury, psychosis, anxiety, depression, dementia, memory and attentiondeficits, Alzheimer's disease, dysmenorrhea, narcolepsy, Reynaud'sdisease, intermittent claudication, Sjorgren's syndrome, migraine,arrhythmia, hypertension, absence seizures, myotonic muscle dystrophia,xerostomi, diabetes type II, hyperinsulinemia, premature labour,baldness, cancer, and immune suppression.

[0235] It is at present contemplated that suitable dosage ranges are 0.1to 1000 milligrams daily, 10-500 milligrams daily, and especially 30-100milligrams daily, dependent as usual upon the exact mode ofadministration, form in which administered, the indication toward whichthe administration is directed, the subject involved and the body weightof the subject involved, and further the preference and experience ofthe physician or veterinarian in charge.

EXAMPLES

[0236] The invention is further illustrated with reference to thefollowing examples which are not intended to be in any way limiting tothe scope of the invention as claimed. TABLE 1 Substituted isatin oximes

Entry R₁ R₂ R₃ R₄ R₅ R₆ Mp. Examples 1a H H H H Br H 250-1 1, 3 1b H CH₃H Cl Cl H 232-6 1, 2, 3 1c H H H H Cl Cl 245-7 1, 3 1d H CH₃ H H Cl Cl140-2 1, 2, 3 1e CH₃ CH₃ H H Cl Cl 180-3 1, 2, 3 1f H H H H—CH═CH—CH═CH— 230 1, 4 1g H H Cl Cl H H 277-8 1, 3 1h CH₃ H Cl Cl HH >250 1, 3 1i CH₃ CH₃ Cl Cl H H 189-91 1, 2, 3 1j H CH₃ Cl Cl H H >2001, 2, 3 1k H CH₂—COOH Cl Cl H H >300 1, 2a, 3 1l t-Bu H Cl Cl H H 220-11, 3 1m

H Cl Cl H H 237-8 1, 3 1n CH₂NHCH₂Ph(4)Cl H Cl Cl H H 232-4 1, 3 1o H HF F H H 263-4 1, 3 1p H H CH₃ CH₃ H H 283-4 1, 3 1q H H H Cl Cl H 274-51, 3 1r CH₂COOH H H H Br H 214-6 1 1s CH₂CO₂Et H H H Br H 167-9 1 1tCH₂COOH H Cl Cl H H 245-6 1, 3 1u H H CH₃ Cl H H >300 1, 3 1v H H CH₃ FH H 286 1, 3 (decomp.) 1w H H O—CH₃ F H H 268-270 1, 3

[0237] Example 1

[0238] 5-Bromoisatin 3-oxime (1a). A mixture of 5-bromoisatin (2.4 g;10.0 mmol), hydroxylamine, hydrochloride (0.76 g; 11 mmol) and sodiumcarbonate (1.1 g; 10.4 mmol) in 96% ethanol (30 ml) was stirred atambient temperature for two hours. Water (50 ml) was added and the crudeproduct was filtered off. Recrystallisation from ethanol afforded pure5-bromoisatin 3-oxime (2.2 g, 91%). Mp. 250-251° C.

[0239] The following compounds were prepared analogously:

[0240] 5,6-dichloro-1-methylisatin 3-oxime (1b) from5,6-dichloro-1-methylisatin. Yield: 79%. Mp. 232-236° C.

[0241] 4,5-dichloroisatin 3-oxime (1c) from 4,5-dichloroisatin. Yield:51%. Mp. 245-247° C.

[0242] 4,5-dichloro-1-methylisatin 3-oxime (1d) from4,5-dichloro-1-methylisatin. Yield: 79%. Mp. 140-142° C.

[0243] O-methyl-4,5-dichloro-1-methylisatin 3-oxime (1e) from4,5-dichloro-1-methylisatin and O-methylhydroxylamine, hydrochloride.The reaction mixture was heated to reflux. Yield: 64%. Mp. 180-183° C.

[0244] Benzo[e]isatin 3-oxime (1f) from benzo[e]isatin. The reactionmixture was heated to reflux. Mp. 230° C.

[0245] 6, 7-dichloroisatin 3-oxime (1g) from 6,7-dichloroisatin. Thereaction mixture was heated to reflux. Yield: 70%. Mp. 277-278° C.

[0246] O-methyl 6,7-dichloroisatin 3-oxime (1h) from 6,7-dichloroisatinand O-methyl hydroxylamine, hydrochloride. The reaction mixture washeated to reflux. Yield: 43%. Mp. >250° C.

[0247] O-methyl 6,7-dichloro-1-methylisatin 3-oxime (1i) from6,7-dichloro-1-methylisatin and O-methyl hydroxylamine, hydrochloride.The reaction mixture was heated to reflux. Yield: 74%. Mp. 189-191° C.

[0248] 6,7-Dichloro-1-methylisatin 3-oxime (1j) from6,7-dichloro-1-methylisatin. The reaction mixture was heated to reflux.Yield: 52%. Mp. >200° C.

[0249] Potassium 2-(6,7-dichloroisatin-1-yl 3-oxime)acetate (1k) from2-(6,7-dichloroisatin-1-yl)acetic acid (Example 2a). The reactionmixture was heated to reflux. The product precipitated as the potassiumsalt upon addition of potassium t-butanolate to an ethanolic solution.Yield: 60%. Mp. >300° C.

[0250] O-t-butyl 6,7-dichloroisatin 3-oxime (1l) from 6,7-dichloroisatinand O-t-butyl hydroxylamine, hydrochloride. The reaction mixture washeated to reflux. Yield: 78%. Mp. 220-221° C.

[0251] O-((4-Phenylpiperazin-1-yl)carbonylmethyl) 6,7-dichloroisatin3-oxime (1m) fromO-((4-phenylpiperazin-1-yl)carbonylmethyl)hydroxylamine, hydrochlorideand 6,7-dichloroisatin. The reaction mixture was heated to reflux.Yield: 76%. Mp. 237-238° C.

[0252] O-(4-Chlorobenzylamino)methyl 6,7-dichloroisatin 3-oxime (1n)from 6,7-dichloroisatin and O-((4-chlorobenzylamino)methyl)hydroxylamine. The reaction mixture was heated to reflux. Yield: 69%.Mp. 232-234° C.

[0253] 6,7-Difluoroisatin 3-oxime (1o) from 6,7-difluoroisatin andhydroxylamine, hydrochloride. The reaction mixture was heated to reflux.Yield: 100%. Mp. 263-264° C.

[0254] 6,7-Dimethylisatin 3-oxime (1p) from 6,7-dimethylisatin andhydroxylamine, hydrochloride. The reaction mixture was heated to reflux.Yield: 98%. Mp. 283-284° C.

[0255] 5,6-Dichloroisatin 3-oxime (1q) from 5,6-dichloroisatin andhydroxylamine, hydrochloride. The reaction mixture was heated to reflux.Yield: 52%. Mp. 274-275° C.

[0256] O-Carboxymethyl 5-bromoisatin 3-oxime (1r) from 5-bromoisatin andO-carboxymethyl hydroxylamine, hydrochloride. THF was used as solventand the reaction mixture was heated to reflux. Yield: 76%. Mp. 214-216°C.

[0257] O-(Ethoxycarbonylmethyl) 5-bromoisatin 3-oxime (1s) from5-bromoisatin and O-(carboxymethyl)hydroxylamine, hydrochloride. Thereaction mixture was heated to reflux and addition of base was omitted.Yield: 6%. Mp. 167-169° C.

[0258] O-(Carboxymethyl) 6,7-dichloroisatin 3-oxime (1t) from6,7-dichloroisatin and O-(carboxymethyl)hydroxylamine, hydrochloride.The reaction mixture was heated to reflux. Yield: 71%. Mp. 245-246° C.

[0259] 6-Chloro-7-methylisatin 3-oxime (1u) from 6-chloro-7-methylisatinand hydroxylamine, hydrochloride. THF was used as solvent and thereaction mixture was heated to reflux. Yield: 56%. Mp. >300° C.

[0260] 6-Fluoro-7-methylisatin 3-oxime (1v) from 6-fluoro-7-methylisatinand hydroxylamine, hydrochloride. THF was used as solvent and thereaction mixture was heated to reflux. Yield: 92%. Mp. 286° C. withdecomposition.

[0261] 6-Fluoro-7-methoxyisatin 3-oxime (1w) from6-fluoro-7-methoxyisatin and hydroxylamine, hydrochloride. THF was usedas solvent and the reaction mixture was heated to reflux. Yield: 87%.Mp. 268-270° C.

[0262] Example 2

[0263] 5,6-dichloro-1-methylisatin (2a). To a solution of5,6-dichloroisatin (0,15 g; 0.7 mmol) in anhydrous DMF (5 ml) was addedsodium hydride (40 mg, 60% dispersion in mineral oil). When theevolution of hydrogen had ceased iodomethane (0.1 ml) was added and themixture was stirred for 20 min. at ambient temperature. Water (15 ml)and glacial acetic acid (0.1 ml) were added and the product was filteredoff, washed with water and dried to yield 5,6-dichloro-1-methylisatin(0.13 g, 81%).

[0264] The following compounds were prepared analogously:

[0265] 4,5-dichloro-1-methylisatin (2b) from 4,5-dichloroisatin, and6,7-dichloro-1-methylisatin from 6,7-dichloroisatin.

[0266] Example 2a

[0267] 2-(6,7-dichloroisatin-1-yl)acetic acid (2c). A solution of5,6-dichloroisatin (1.0 g, 4.65 mmol) in DMF (20 ml) was cooled in anice-bath. Sodium hydride (5.11 mmol, 0.20 g 60% dispersion in mineraloil) was added and the mixture was stirred for 20 min. Ethyl2-bromoacetate (0.37 ml, 5.11 mmol) was added and stirring was continuedfor 2 hours. The resulting mixture was poured into diluted hydrochloricacid (200 ml, 4 M), heated to reflux for 2 hours, filtered, cooled andextracted with ethyl acetate. The organic extract was dried overmagnesium sulphate and evaporated to dryness to leave the desiredproduct (0.85 g, 67%).

[0268] Example 3

[0269] The following isatins were prepared according to the aboveScheme, by the procedure described in Organic Syntheses, Coll. Vol. I p.327.

[0270] 5,6-dichloroisatin (3a) and 4,5-dichloroisatin (3b) were preparedas a mixture of isomers from 3,4-dichloroaniline. The isomers wereseparated by fractionated crystallisation from ethylacetate.

[0271] 6,7-dichloroisatin (3c) was prepared from 2,3-dichloroaniline.

[0272] 6,7-difluoroisatin (3d) was prepared from 2,3-difluoroaniline.

[0273] 6,7-dimethylisatin (3e) was prepared from 2,3-dimethylaniline.

[0274] 6-chloro-7-methylisatin (3f) was prepared from3-chloro-2-methylaniline.

[0275] 6-fluoro-7-methylisatin (3g) was prepared from3-fluoro-2-methylaniline.

[0276] 6-fluoro-7-methoxyisatin (3h) was prepared from3-fluoro-o-anisidine.

[0277] Example 4

[0278] Benzo[e]isatin (4a). A mixture of diethyl oxomalonate (1.4 ml; 9mmol), 2-aminonaphtalene (1 g; 7 mmol) and sodium carbonate (0.2 g; 1.9mmol) in acetic acid (15 ml) was heated to reflux for 10 min. Thesolvent was removed by evaporation and the residue was suspended inaqueous sodium hydroxide (4 M, 30 ml). The suspension was heated toreflux for 5 hours, during which time air was bobbled through thereaction mixture. The cooled mixture was acidified with dilutedhydrochloric acid and the crude product was filtered off.Recrystallisation from ethanol afforded pure benzo[e]isatin (0.3 g. Mp.245° C).

[0279] Example 5

[0280] Electrophysiological Experiments

[0281] In this example, the biological activity of the compounds of theinvention is demonstrated using electrophysiologic patch-clamptechniques.

[0282] Intermediate-conductance Ca²⁺-activated K⁺ channels (IK channels)have been cloned from human placenta and stably expressed in HEK293cells. The ionic current through the channels is recorded in thewhole-cell mode of the patch-clamp technique.

[0283] Stable Expression of IK in HEK293 Cells

[0284] Human IK (hIK) was excised from pT3T7 (GenBank Acc. No. N56819)using EcoR I and Not I, and subcloned into the mammalian expressionvector pNS1Z (NeuroSearch), a custom designed derivative of pcDNA3Zeo(InVitrogen), to give the plasmid construct pNS1Z_hIK.

[0285] HEK293 tissue culture cells were grown in DMEM (Dulbecco'sModified Eagle Medium) supplemented with 10% FCS (foetal calf serum) at37° C. in 5% CO₂. One day prior to transfection, 10⁶ cells were platedin a cell culture T25 flask. The following day, cells were transfectedusing lipofection (20 μL Lipofectamin™, Life Technologies, with 2.5 μgof the plasmid pNS1Z_hIK in a total volume of 540 μL).

[0286] The lipofection mixture was overlaid on the cells and incubatedat 37° C. for 5 hours. The cells were then rinsed with regular media andgrown for 72 hours in DMEM, 10% FCS at 37° C. in 5% CO₂.

[0287] 72 hours post transfection, cells transfected with pNS1Z_hIK wereselected in media supplemented with 0.25 mg/ml Zeocin. Single cloneswere picked and propagated in selection media until sufficient cells forfreezing were available. Hereafter the cells were cultured in regularmedium without selection agent.

[0288] Expression of functional hIK channels was verified by patch-clampmeasurements.

[0289] Whole Cell Recordings

[0290] Experiments are carried out on one of several patch-clampset-ups. Cells plated on coverslips are placed in a 15 μl perfusionchamber (flowrate ˜1 ml/min) mounted on a IMT-2 microscope equipped withNomarski or Hoffmann optics. The microscopes are placed onvibration-free tables in grounded Faraday cages. All experiments areperformed at room temperature (20-22° C.). EPC-9 patch-clamp amplifiers(HEKA-electronics, Lambrect, Germany) are connected to Macintoshcomputers via ITC16 interfaces. Data are stored directly on the harddiskand analysed by the IGOR software (WaveMetrics, Lake Oswega, USA).

[0291] The whole-cell configuration of the patch clamp technique isapplied. The tip of a borosilicate pipette (resistance 2-4 MΩ) is gently(remote control system) placed on the cell membrane. Light suctionresults in a giga seal (pipette resistance increases to more than 1 GΩ)and the cell membrane is then ruptured by more powerful suction. Cellcapacitance is electronically compensated and the resistance between thepipette and the cell interior (the series resistance, Rs) is measuredand compensated for. Usually the cell capacitance ranges from 5 to 20 pF(depending on cell size) and the series resistance is in the range 3 to6 MΩ. Rs- as well as capacitance compensation are updated during theexperiments (before each stimulus).

[0292] All experiments with drifting Rs-values are discharged.Leak-subtractions are not performed.

[0293] Solutions

[0294] The following five compounds, 1a, 1g, 1h, 1i and 1j of Table 1,were subjected to this experiment.

[0295] The extracellutar (bath) solution contains: 144 mM KCl, 2 mMCaCl₂, 1 mM MgCl₂, 10 mM HEPES (pH=7.4). Test compounds are dissolved inDMSO from stock solution and then diluted to a final concentration ofabout 10 μM in the extracellular solution. The concentration of CaCl₂ is7.6 mM and that of MgCl₂ is 1.2 mM to give calculated freeconcentrations of 300 nM and 1 mM, respectively.

[0296] Quantification

[0297] After establishment of the whole-cell configuration,voltage-ramps (usually −100 to +100 mV) are applied to the cell every 5sec. A stable baseline current is obtained within a period of 100-300seconds, and the compounds are then added by changing to anextracellular solution containing the compound to be tested. Very littleendogen current (<200 pA at 100 mV, compared to 2-20 nA IK current) areactivated under these circumstances in native HEK293 cells.

[0298] Results

[0299] All compounds tested in this experiment showed activity at afinal concentration of about 10 μM or less, and these compoundstherefore are potent SK/IK channel activating agents of the invention.

1. Use of an isatin derivative represented by the general formula

or a pharmaceutically acceptable salt or an oxide or a hydrate thereof,wherein, R¹ represents hydrogen; an alkyl group; a cycloalkyl group; anacyl group; a phenyl or a benzyl group, which phenyl and benzyl groupsmay be substituted one or more times with substituents selected fromhalogen, —NO₂, —CN, —CF₃, alkyl, cycloalkyl, hydroxy, and alkoxy; agroup of the formula —CH₂CN; a group of the formula —CH₂CO₂R′, whereinR′ represents hydrogen or alkyl; a group of the formula—CH₂CONR^(IV)R^(V), wherein R^(IV) and R^(V) independently representshydrogen, alkyl, phenyl or benzyl, which phenyl and benzyl groups mayoptionally be substituted one or more times with halogen and/or alkyl,or R^(IV) and R^(V) together with the N-atom to which they are attachedform a heterocyclic 4 to 7 membered monocyclic group, which heterocyclicgroup may optionally be substituted one or more times with substituentsselected from the group consisting of halogen, alkyl, cycloalkyl,alkyloxy, cycloalkyloxy, phenyl or benzyl; or a group of the formula—CH₂C(═NOH)NH₂; R² represents hydrogen; an alkyl group; a cycloalkylgroup; a group of the formula —CH₂CO₂R′, wherein R′ represents hydrogenor an alkyl group; a phenyl or a benzyl group, which phenyl and benzylgroups may be substituted one or more times with substituents selectedfrom halogen, —NO₂, —CN, —CF₃, alkyl, cycloalkyl, hydroxy, and alkoxy;and R³, R⁴, R⁵, and R⁶ independently of each another representshydrogen; halogen; —NO₂; —CN; —CF₃; an alkyl group; an alkoxy group; aphenyl or a benzyl group, which phenyl and benzyl groups may besubstituted one or more times with substituents selected from halogen,—NO₂, —CN, —CF₃, alkyl, cycloalkyl, hydroxy, and alkoxy; or a group ofthe formula —SO₂NR″R′″, wherein R″ and R′″ independently of each anotherrepresents hydrogen or an alkyl group; or R⁵ and R⁶ are as definedabove, and R³ and R⁴ together form an additional 4 to 7 membered fusedring, which fused ring may be aromatic, saturated or partiallysaturated, and which fused ring may optionally be substituted one ormore times with substituents selected from the group consisting ofhalogen, —NO₂, —CN, —CF₃, and a group of the formula —SO₂NR″R′″, whereinR″ and R′″ independently of each another represents hydrogen or an alkylgroup; for the manufacture of a medicament for the treatment oralleviation of a disease or disorder or condition that is responsive toactivation of SK_(Ca) and/or IK_(Ca) channels.
 2. The use according toclaim 1, wherein R¹ of formula I represents hydrogen; a C₁₋₆-alkylgroup; a phenyl group; a benzyl group; a group of the formula —CH₂CO₂R′,wherein R′ represents hydrogen or a C₁₋₆-alkyl group; a group of theformula —CH₂NH-Z, wherein Z represents phenyl or benzyl, which phenyland benzyl may optionally be substituted one or more times with halogen;or a group of the formula —CH₂CO—Y, wherein Y represents a heterocyclic6 membered monocyclic group containing at least one nitrogen atom as theheteroatom, and which heterocyclic group may optionally be substitutedone or more times with a C₁₋₆-alkyl group or a phenyl group.
 3. The useaccording to claim 2, wherein Y represents a piperidinyl or apiperazinyl group.
 4. The use according to either of claims 1-3, whereinR² of formula I represents hydrogen, C₁₋₆-alkyl, phenyl, benzyl, or agroup of the formula —CH₂COOH.
 5. The use according to any of claims1-4, wherein R³, R⁴, R⁵, and R⁶ of formula I independently of eachanother represents hydrogen, F, Br, Cl, NO₂, CN, CF₃, or C₁₋₆-alkyl. 6.The use according to any of claims 1-4, wherein the isatin derivative isrepresented by the general formula

or a pharmaceutically acceptable salt or an oxide or a hydrate thereof,wherein, R¹, R², R⁵ and R⁶ are as defined above; and X represents asubstituent selected from the group consisting of hydrogen, halogen,—NO₂, —CN, —CF₃, and a group of the formula —SO₂NR″R′″, wherein R″ andR′″ independently of each another represents hydrogen or an alkyl group.7. The use according to claim 1, wherein the isatin derivative is5,7-dinitro-1-methyl-1 H-indole-2,3-dione-3-(O-methyloxime);5-bromo-7-nitro-1 H-indole-2,3-dione-3-oxime; 5,7-dinitro-1 -methyl-1H-indole-2,3-dione-3-oxime; 5-nitro-1 H-benz[g]indole-2,3-dione-3-oxime;5-nitro-1 H-6,7,8,9-tetrahydro-benz[g]indole-2,3-dione-3-oxime;5,7-dinitro-1-methyl-1 H-indole-2,3-dione-3-(O-methyloxime);5,7-dinitro-1 H-indole-2,3-dione-3-(O-methyloxime);5,7-dinitro-1-ethyl-1 H-indole-2,3-dione-3-(O-methyloxime);5-nitro-3-(O-methyloxime)-1 H-indole-2,3-dione; 1-phenyl-1H-indole-2,3-dione-3-(O-methyloxime); 1H-indole-2,3-dione-3-(O-methyloxime); 5,7-dibromo-1-methyl-1H-indole-2,3-dione-3-(O-methyloxime); 5,7-dibromo-1H-indole-2,3-dione-3-(O-methyloxime); 1-methyl-5-nitro-1H-indole-2,3-dione-3-(O-methyloxime); 5,6-dichloro-1-methyl-1H-indole-2,3-dione-3-(O-methyloxime); 4,5-dichloro-1-methyl-1H-indole-2,3-dione-3-(O-methyioxime); 5,7-dinitro-1-benzyl-1H-indole-2,3-dione-3-(O-methyloxime); 4,6-ditrifluoromethyl-1-methyl-1H-indole-2,3-dione-3-(O-methyloxime);5-nitro-7-trifluoromethyl-1-methyl-1H-indole-2,3-dione-3-(O-methyloxime); 5-nitro-7-trifluoromethyl-1H-indole-2,3-dione-3-(O-methyloxime); 5,7-dinitro-6-methoxy-1-methyl-1H-indole-2,3-dione-3-(O-methyloxime);5,7-dinitro-1-(O-ethylcarboxymethyl)-1H-indole-2,3-dione-3-(O-methyloxime); 5-nitro-1-methyl-1H-benz[g]indole-2,3-dione-3-(O-methyloxime);5-bromo-1-ethoxycarbonylmethyl)-1 H-indole-2,3-dione-3-(O-methyloxime);5,7-dibromo-1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione-3-(O-methyloxime);5-methyl-1-(methoxycarbonylmethyl)-1H-indole-2,3-dione-3-(O-methyloxime); 5-nitro-1-methyl-1H-6,7,8,9-tetrahydro-benz[g]-indole-2,3-dione-3-(O-methyloxime); 1H-benz[g]indole-2,3-dione-3-oxime; 5,7-dinitro-1-methyl-1H-indole-2,3-dione-3-oxime; 5,7-dibromo-1 H-indole-2,3-dione-3-oxime;5-bromo-1-methyl-1 H-indole-2,3-dione-3-oxime; 5,7-dinitro-1H-indole-2,3-dione-3-oxime; 5-bromo-7-nitro-1H-indole-2,3-dione-3-oxime; 5-bromo-1 H-indole-2,3-dione-3-oxime;5-nitro-1 H-indole-2,3-dione-3-oxime; 5-methyl-1H-indole-2,3-dione-3-oxime; 1 H-indole-2,3-dione-3-oxime;1-methyl-6,7,8,9-tetrahydro-1 H-benz[g]indole-2,3-dione-3-oxime;5,6-dichloro-1-methyl-1 H-indole-2,3-dione-3-oxime; 4-phenyl-7-methoxy-1H-indole-2,3-dione-3-oxime; 4,5-dichloro-1 H-indole-2,3-dione-3-oxime;1-phenyl-1 H-indole-2,3-dione-3-oxime; 4,5-dichloro-1-methyl-1H-indole-2,3-dione-3-oxime; 5-nitro-1 H-benz[g]indole-2,3-dione-3-oxime;5-nitro-7-trifluoromethyl-1-methyl-1 H-indole-2,3-dione-3-oxime;5-nitro-7-trifluorimethyl-1 H-indole-2,3-dione-3-oxime; 5-nitro-1H-6,7,8,9-tetrahydro-benz[g]indole-2,3-dione-3-oxime; 5-fluoro-7-nitro-1H-indole-2,3-dione-3-oxime; 5,7-dinitro-1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione-3-oxime; 1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione-3-oxime; 5-bromo-1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione-3-oxime; 5,7-dinitro-1 H-indole-2,3-dione-3-oxime;5,7-dinitro-1 H-indole-2,3-dione-3-(O-benzyloxime); 5,7-dinitro-1H-1-benzyl-indole-2,3-dione-3-(O-benzyloxime); 5,7-dinitro-1-methyl-1H-indole-2,3-dione-3-(Obenzyloxime);5,7-dinitro-1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione-3-(O-benzyloxime); 5-nitro-1-(ethoxycarbonylmethyl)-1H-indole-2,3-dione-3-(O-benzyloxime); 1-methoxy-1H-indole-2,3-dione-3-oxime; 1-acetyl-5-bromo-1 H-indole-2,3-dione;1-hydroxy-1-H-indole-2,3-dione-3-oxime; 5-bromoisatin 3-oxime;5,6-dichloro-1-methylisatin 3-oxime; 4,5-dichloroisatin 3-oxime;4,5-dichloro-1-methylisatin 3-oxime;O-methyl-4,5-dichloro-1-methylisatin 3-oxime; benz[e]isatin 3-oxime;6,7-dichloroisatin 3-oxime; O-methyl 6,7-dichloroisatin 3-oxime;O-methyl 6,7-dichloro-1-methylisatin 3-oxime;6,7-dichloro-1-methylisatin 3-oxime; potassium2-(6,7-dichloroisatin-1-yl 3-oxime)acetate; O-t-butyl 6,7-dichloroisatin3-oxime; O-((4-phenylpiperazin-1-yl)carbonylmethyl) 6,7-dichloroisatin3-oxime; O-(4-chlorobenzylamino)methyl 6,7-dichloroisatin 3-oxime;6,7-difluoroisatin 3-oxime; 6,7-dimethylisatin 3-oxime;5,6-dichloroisatin 3-oxime; O-carboxymethyl 5-bromoisatin 3-oxime;O-(ethoxycarbonylmethyl) 5-bromoisatin 3-oxime; O-(carboxymethyl)6,7-dichloroisatin 3-oxime; 6-chloro-7-methylisatin 3-oxime;6-fluoro-7-methylisatin 3-oxime; or 6-fluoro-7-methoxyisatin 3-oxime; ora pharmaceutically acceptable salt or an oxide or a hydrate thereof. 8.The use according to any of claims 1-7, wherein the disease or conditionis a respiratory disease such as asthma, cystic fibrosis, chronicobstructive pulmonary disease and rhinorrhea, convulsions, vascularspasms, coronary artery spasms, renal disorders, polycystic kidneydisease, bladder spasms, urinary incontinence, bladder outflowobstruction, irritable bowel syndrome, gastrointestinal dysfunction,secretory diarrhoea, ischaemia, cerebral ischaemia, ischaemic hearthdisease, angina pectoris, coronary hearth disease, traumatic braininjury, psychosis, anxiety, depression, dementia, memory and attentiondeficits, Alzheimer's disease, dysmenorrhea, narcolepsy, Reynaud'sdisease, intermittent claudication, Sjorgren's syndrome, migraine,arrhythmia, hypertension, absence seizures, myotonic muscle dystrophia,xerostomi, diabetes type II, hyperinsulinemia, premature labour,baldness, cancer, and immune suppression.
 9. An isatin derivativerepresented by the general formula

or a pharmaceutically acceptable salt or an oxide or a hydrate thereof,wherein, R¹ represents hydrogen; a C₁₋₆-alkyl group; a group of theformula —CH₂CO₂R′, wherein R′ represents hydrogen or C₁₋₃-alkyl; a groupof the formula —CH₂NH-Z, wherein Z represents phenyl or benzyl, whichphenyl and benzyl may optionally be substituted one or more times withhalogen; or a group of the formula —CH₂CO—Y, wherein Y represents aheterocyclic 6 membered monocyclic group containing at least onenitrogen atom as the heteroatom, and which heterocyclic group mayoptionally be substituted one or more times with a C₁₋₆-alkyl group or aphenyl group; R² represents hydrogen; a C₁₋₆-alkyl group; a group of theformula —CH₂CO₂R′, wherein R′ represents hydrogen or an alkyl group; andR³, R⁴, R⁵, and R⁶ independently of each another represents hydrogen,halogen or a C₁₋₃-alkyl group; or R⁵ and R⁶ are as defined above, and R³and R⁴ together form an additional 6 membered aromatic or heteroaromaticfused ring.
 10. The isatin derivative according to claim 9, which is5-bromoisatin 3-oxime; 5,6-dichloro-1-methylisatin 3-oxime;4,5-dichloroisatin 3-oxime; 4,5-dichloro-1-methylisatin 3-oxime;O-methyl-4,5-dichloro-1-methylisatin 3-oxime; benz[e]isatin 3-oxime;6,7-dichloroisatin 3-oxime; O-methyl 6,7-dichloroisatin 3-oxime;O-methyl 6,7-dichloro-1-methylisatin 3-oxime;6,7-dichloro-1-methylisatin 3-oxime; potassium2-(6,7-dichloroisatin-1-yl 3-oxime)acetate; O-t-butyl 6,7-dichloroisatin3-oxime; O-((4-phenylpiperazin-1-yl)carbonylmethyl) 6,7-dichloroisatin3-oxime; O-(4-chlorobenzylamino)methyl 6,7-dichloroisatin 3-oxime;6,7-difluoroisatin 3-oxime; 6,7-dimethylisatin 3-oxime;5,6-dichloroisatin 3-oxime; O-carboxymethyl 5-bromoisatin 3-oxime;O-(ethoxycarbonylmethyl) 5-bromoisatin 3-oxime; O-(carboxymethyl)6,7-dichloroisatin 3-oxime; 6-chloro-7-methylisatin 3-oxime;6-fluoro-7-methylisatin 3-oxime; or 6-fluoro-7-methoxyisatin 3-oxime; ora pharmaceutically acceptable salt or an oxide or a hydrate thereof. 11.A pharmaceutical composition comprising a therapeuticallly-effectiveamount of the isatin derivative according to any of claims 9-10, or apharmaceutically-acceptable addition salt thereof, together with atleast one pharmaceutically-acceptable carrier or diluent.
 12. Thepharmaceutical composition according to claim 11, for use in thetreatment or alleviation of a disease or disorder or conditionsresponsive to activation of SK_(Ca) and/or IK_(Ca) channels.
 13. Thepharmaceutical composition according to claim 12, for use in thetreatment or alleviation of respiratory diseases such as asthma, cysticfibrosis, chronic obstructive pulmonary disease and rhinorrhea,convulsions, vascular spasms, coronary artery spasms, renal disorders,polycystic kidney disease, bladder spasms, urinary incontinence, bladderoutflow obstruction, irritable bowel syndrome, gastrointestinaldysfunction, secretory diarrhoea, ischaemia, cerebral ischaemia,ischaemic hearth disease, angina pectoris, coronary hearth disease,traumatic brain injury, psychosis, anxiety, depression, dementia, memoryand attention deficits, Alzheimer's disease, dysmenorrhea, narcolepsy,Reynaud's disease, intermittent claudication, Sjorgren's syndrome,migraine, arrhythmia, hypertension, absence seizures, myotonic muscledystrophia, xerostomi, diabetes type II, hyperinsulinemia, prematurelabour, baldness, cancer, and immune suppression.
 14. A method oftreatment or alleviation of a disease or disorder or condition of aliving animal body, including a human, which disorder or disease orcondition is responsive to activation of SK_(Ca) and/or IK_(Ca)channels, comprising the step of administering to such a living animalbody, including a human, in need thereof a therapeutically effectiveamount of a compound according to claim
 9. 15. The method according toclaim 15, in which the disease or disorder or condition is a respiratorydisease such as asthma, cystic fibrosis, chronic obstructive pulmonarydisease and rhinorrhea, convulsions, vascular spasms, coronary arteryspasms, renal disorders, polycystic kidney disease, bladder spasms,urinary incontinence, bladder outflow obstruction, irritable bowelsyndrome, gastrointestinal dysfunction, secretory diarrhoea, ischaemia,cerebral ischaemia, ischaemic hearth disease, angina pectoris, coronaryhearth disease, traumatic brain injury, psychosis, anxiety, depression,dementia, memory and attention deficits, Alzheimer's disease,dysmenorrhea, narcolepsy, Reynaud's disease, intermittent claudication,Sjorgren's syndrome, migraine, arrhythmia, hypertension, absenceseizures, myotonic muscle dystrophia, xerostomi, diabetes type II,hyperinsulinemia, premature labour, baldness, cancer, and immunesuppression.